To create a Facebook SSO login, you’ll need to follow these steps:

Login into Meta for developers and click on your FB App -> Login with FB. Under Valid OAuth Redirect URIs add your Webstore’s domain using this format:

https\://YOUR\_STORE\_SUB\_DOMAIN.YOUR\_STORE\_DOMAIN.com/login

Then under Allowed Domains for the JavaScript SDK add your Webstore’s domain using this format:

https\://YOUR\_STORE\_SUB\_DOMAIN.YOUR\_STORE\_DOMAIN.com/